Plug



Aug- 18, 1931- N. c: sc:|-1EL| E1-1GER` 1,819,040

PLUG

Filed April 18, 1925 3 Smets-SheetI l C? Q7 f J@ l (36- 3/2 V 4 W4 f "WP- b Wi/Waimes:l Ma... f/ig #M7 MM2 Y l f Aug' l8,-1931 y N. c. scHl-:LLENGER 1,819,040

' PLUG i Filed April 18, 1925 A 5 Sheets-Sheet 2 vug. S, 1931. N, C, SCHELLENGER i 1,819,040

PLUG

Filed April 18, 1s25` 3 sheets-sheet 5 Patented Aug. 18,1931` UNITED STATES PATENT OFFICE NEWTON C. SCHELLENGER, OF ELKHART, INDIANA, ASSIGNOR TO CHICAGO TELEPHONE SUPPLY COMPANY, 1Ofl ELKHART, INDIANA, A CORPORATION OF DELAWARE PLUG Application filed April 18, 1925. Serial N0. 24,002.

The present invention relates to connectors which are particularly adapted for use in radio or telephone plugs, but are not limited to such use.

5 In plugs of this type,'it is often desirable to be able lto readily connect or detach the connecting tip at the end of thefiexible cord with the terminal members of the plug. Accordingto my invention I provide a pair of connectors preferably inthe form of spring members which are electrically connectedto the tip and sleeve portions of the plug respectively and to which the tips provided at the end of a flexible cord may be attached 5 or from Which they may be detached with facility.

The terminals now almost universally employed on flexible telephone cords, comprise a socket or sleeve of a diameter great enough to receive the end of the conducting strand and its sleeve of insulation which socket or sleeve has on extension of reduced diameter known as a pin type terminal.

I am aware that it is old to grip this reduced portion or pin by a spring or by a spring held clutch but I wish to call attention to the fact that I am the iirst to provide means for making electrical Contact and mechanical holding engagement with'the sleeve or socket portion of the terminal. i

There are many ways in which the sleeve or socket portions of the terminals may b e gripped but the simplest and cheapest way is to provide a spring which bears against the side of the terminal and has ashoulder which hooks over the end of the sleeve or socket. Any suitable means may be provided, for example, a recess in the handle or body of the plug for holding the terminal against side- Wise displacement. l Y The terminal may be held between two such springs and more than one cord terminal may be connected to one Contact of the plug. The shoulder instead of being formed.

on the spring may be formed in the casing. The novel action involved in either case is that lateral movement of the spring against the contact socket or terminal holds the saidterminal under a shoulder.

the sleeve. -ple soldering the ends4 may be relied upon.

have shaped the ends of the springs in such a manner that the cord tips may be easily released from the grip of the springs with which they are in contact by pressing these ends together. v

Another important feature of the invention is the provision of a novel contact sleeve for the plug. In the construction of telephone plugs as now made the sleeve Contact is made of a piece of drawn brass tubing which must beheld to close limits both inside and outside so that it will fit the jacks not only of one manufacturer but of all other manufacturers. As a result this sleeve is expensive and difficult to make. Furthermore, good contact cannot always be maintained because wear of any extent makes the plug lit loosely in the jack and the lateral pressure of the jack springs is the only thing which keeps the parts lin contact.

I propose according to my present invention to make this sleeve contact slightly expansible so that the tolerances may be made much greater and yet the fit of the parts will be at all times good even if worn. According to my invention I may slit the sleeve longitudinally and bulge the central part thereof outwardly to secure the expansible effect but this is not the preferred way because it increases the cost of a part which is already too expensive.

According tothe preferred mode of carrying out my invention I form the sleeve by winding a flat strip helically about an arbor. This produces two desirable results; first it greatly cheapens the cost' of the sleeve and second it gives it the desired expansability or resiliency to produce good contact. To keep the ends of the spiral strip from spring- `ing out or unraveling I provide restraining means at the ends preferably in the shape of caps or rings which chuck the ends of Other means as for exam- I may form the sleeve by punching out a flat piece to provide longitudinal or spiral slots and then die forming the flat piece into a sleeve, the slots extending along only the central part to give. the desired resiliency for contact.

unless the springs 28 and 30 are pressed t0- ward each other. This, because, the'upper edge of the cord tips engages with the underside of the laterally extending portions 38 and 39, which form shoulders, the hole 70 being moved out of register vith the sleeve by lateral movement of the main body of the spring 28 or 30.

Spring terminals 2S and 30 are also provided With longitudinal openings with which the cord tips are adapted to cooperate 'for the purpose of making Contact as shown in Figure 2. It will be seen that the edges of each opening make Contact on two sides of each cord tip as indicated at 40 and 4l; the

ends of the tips being-adapted for seating in the upper ends of the rib members 35. By being held in this manner, the cord tips are prevented from moving in any direction, and are therefore firmly secured in position. The openings 42 and 43 in which the cord tips lie, are relatively oblong in shape and extend longitudinally of the terminal springs 28 and 30 respectively.

`In another embodiment of my invention shown in Figure 3, the terminal springs 44 and 45 do not have the longitudinal openings as designated by 42 and 43 in Figure 2, nor are they provided with the bent portions 38 and 39 with the openings 70 therein.

The springs 44 and 45, in this case, except for y the bent portions which are secured to the needle and retaining washer, 'are substantially flat and have no openings for the cord tips. The housing 46. however, has an inwardly projecting flange 47 against the underside of which the cord tips 4S and-49 may abut so as to prevent their being pulled out of contact Withthe terminal springs 44and 45 by a pull in the longitudinal direction on the cord to which these tips are seeured.` The tips 48 and 49 may be released from the grip of the spring members 44 and 45 by means of the pins 50. These pins are secured to the inner faces ofthe springs 44 and 45 and preferably on diagonally opposite corners thereof. By fastening them in this manner, it has been found that it is easier to release the cordtips fromv the grip of the springs.

In the modification shown in Figure 5, the spring terminals 51 and 52 are formed as shown in Figure l0, which is an isometric view of-spring 51 the contact portion of t-his spring which is adapted to fit overthe needle 24 is bent at relatively right angles to the major or longitudinal portion of the spring proper. The upper end is bent over on itself and is provided with the protecting lug or linger 53 which is adapted to hook into the upper end of the socket so as to prevent the terminal from being pulled out of "contact with itscooperating spring. The housingl is similar in construction to the housing '32 as illustrated in Figure l.

Figure 6 is an embodiment, showinga further modication of the terminal springs.

In this case, t-he springs 53 and 54 are also provided with bent portions at one end which have .openings therein adapted to tit over the retaining washer 26 and the needle 24, re spectively, and form engaging shoulders for holding the ends of the terminals. From the isometric view of the terminal spring 53, shown in Figure 9, it will be seen that-it has a depressed portion or trough 55 in which the cord tip is adapted to lie. The depression 55 is relatively circular in shape so that surface contact over a large area of the tip 36 may be had. This is also true of the cord tip 37 with reference to its spring 54. The projecting' pin portions of each of the cord tips 36 and 37 extend beyond the depressed 'portions in the springs and may make line contact with them. Each of these springs is provided with the end portions 56 and 57 which are bent inwardly for ease in handling. The ends may be pressed toward each other When it is desired to insert or release the tips 36 and 37.

A further modification of a spring terminal member is shown in Figure 8. In this modification, a longitudinal opening 58 is provided, of which the narrow or slot portion 59 is adapted to make contact on two sides of the protecting pin part of the cord tips. It merges into a wider portion 6() which makes contact on two sides of the cylindrical barrel portion of the tips. A lug 6l projects into the opening 60 and serves to engage with the upper end of the cord tip so as to hold it firmly in place when it is slipped into the opening 58. By using this type of spring, the cord tips may be released by drawing in the end at the upper portion 62 the same as in the other types of springs described.

In Figures 11, l2 and 13, the sleeve and pin portions of the plug have been enlarged so as to bring out, especially, the novel construction of the sleeve. The sleeve is spirally wound, and is held in place by the retaining washers 23 and26 as hereinabove described. Each of these washers has a conical surface into which the respective ends of the sleeve are adaptedto fit. It vhas been found that by 'this construction, the sleeve is prevented from springing out at the ends thereby insuring its permanency of form. Vvvhen sleeve 20 is held in this manner by the retaining washers, it has also beenfound to be slightly greater in diameter at the center as shown at a and b than it is at the ends where it is held by the retaining washers. This gives the sleeve a spring-like character which permits it to fit snugly into the opening with which itis to contact.

In the embodiment of my invention'shown in Fig. 14, the metal Contact sleeve 65 is of the tube type and has its ends counterbored to receive\the insulating washers 66 and 67. A needle 68 tits snugly in the openings in the opposite end of the needle 68 projects beyond the insulating Washer 67 so as to receive the Contact spring 71, the insulating disk 72, the

contact spring 73, and the nut 74 which retains these members 1n place. The contact spring 71 is provided with an opening 1n its Ilower portion, the diameter of which is ,greater than that ofthe needle 68 which j la"l vpasses.through it. Along the edge of this opening is an extruded rim 75, which snugly fits int-o the eounterbore in the outer sleeve 65 and' seats on the end of sleeve 65. In this l Way, not only is better contact had between lthe Contact spring 71 and the sleeve 65, but the spring 71 is also firmly seated and is less apt to Work itself loose. The insulating disk 72 serves to separate the springs 71 and 73 from each other. By tightening the nut 74 on the needle 68, the springs 71 and 73 will be firmly held in position. Loosening up the nut 74 is prevented by either riveting the end of the needle over the nutvor soldering the end of the needle.

The Contact spring 78 which is shown in full in Figure 17 consists of a main body portion 75 and a foot portion 76 Which makes contact with the needle 68 and which is at substantially right angles to the main body portion 75. The body portion 75 is `divided into a fiat spring portion and a cylindrical rigid or contact portion 77. the outer end of Which has a lug or handle 78, by Which the spring portion may be iexed and the contact portion 77 controlled or moved. An opening 79 is provided in semi-circular portion 77 adjacent the lug 78 and a small-lug or catch is struck out of the edge of the hole 79. The Contact spring 71 is in all essential respects similar to the contact spring 73 except that the foot portion has an'opening in it which is greater in diameter than' the needle 68 and also has the projecting rim 75.

The base 81 is provided with a central opening Whichreceives the sleeve as by means of a press fit. It is provided with a flange portion 82 and a cylindrical knurled mounting portion 83. The housing or sleeve 84 is secured to the base 81 being pressed thereon. As the housing 84 is of the same size and shape at both ends, either end may be fitted to the mounting portion 83, and once it is pressed upon the portion 83, its position is permanent.

In Fig. 15. the cord tips 85 and 86 are shown in contact With the ,springs 73 and 71,

respectively. When the c'ord tips are inserted in the plug, the projecting lug or catch 80 will lie Within the sleeve of the cord tip 85 or 86. The outer Wall of the sleeve of the cord tip will have substantially surface Contact with the semi-circular portion of the spring 77, and lie against the inner Wall of the housing 84. The cord tip may be released from the grip of the spring by drawing in the upper portion of the spring by means of thelug 78 in substantially the same manner as in the other types of springs described.

In each of the different embodiments of plugs shown and described, the contact sleeve member, tip contact, insulating Washer, retaining washers, the central needle, and the inner sleeve of insulation separating the contact sleeve member fromthe central needle are the same as those used in the embodiment shown in Figure 1. The novel features of the other embodiments being particularly directed to the spring terminal members and the housings for same.

I do not intend to be limited to the details shown or described.

I claim:

1. An electric connectand disconnect plug having ay sleeve of spirally Wound material and means for holding the ends of same.

2. In a plug, a sleeve of spirally Wound material, retaining Washers for the ends of said sleeve, the inner faces of said Washers being conical in shape.

3. In combination, a plug having a sleeve of spirally wound material, said sleeve having a diameter which is greater at the center than at the end so as to make it spring acting.

4. An electric contact plug comprising a spirally Wound sleeve for insertion into a jack, means for preventing saidsleeve from unraveling, said means including a pair of retaining washers.

5. In combination, a needle, an insulating sleeve mounted on said needle, a spirally Wound sleeve over said insulating sleeve, and means for holding said spirally Wound sleeve fixed relative said needle.

6. In combination, a needle threaded at one end and having a tip contact mounted thereon, an insulating Washer adjacent said tip contact, an insulating sleeve mounted on said needle and adjacent said insulating washer, a retaining Washer mounted on said insulating sleeve and adjacent said insulating Washer, a spirally wound sleeve on said insulated sleeve and having one end engaged in said retaining Washer and a second retaining Washer mounted on said needle and adapted to engage with the opposite end of said spirally Wound sleeve.

7. In combination, a needle threaded at one end having a contact tip fitted thereon, an insulating Washer adjacent said Contact tip, and insulating sleeve mounted on said needle and adjacent saidinsulatingwasher, a spirally Wound sleeve mounted over said insulating sleeve, a retaining Washer on said insulating sleeve for engaging one end of said spirally Wound sleeve to prevent same from unraveling, and a metal cap tightly fitted over the opposite end of said spirally wound sleeve.

8. In combination, a needle threaded at both ends and having a contact tip at one end, an insulating washer adjacent said tip, an insulating sleeve adjacent said washer, a spirally wound sleeve over said insulating sleeve and means for securely holding the ends of said spiral sleeve fixed with reference to said needle, a metal cap tightly fitted over said spiral sleeve, and a pair of spring terminal members mounted on said needle and adjacent said cap.

9. In combination, a needle having an insulating sleeve thereon, a spiral sleeve fitted over said insulating sleeve, a retaining washer for said spiral sleeve and a terminal member adapted to cooperate with said retaining washer so as to be electrically connected to said sleeve.

10. In combination, a needle having an insulating sleeve mounted thereon, a spiral sleeve fitted over said insulating sleeve, a retaining washer for said spiral sleeve, a terminal member adapted for contact with-said retaining washer, an insulating washer adjacent saidterminal member and a second terminal member adjacent said insulating washer and secured to said needle by means fitted over the end thereof. y

11. In combination, a pair of cord tips, a needle. a spiral sleeve mounted on said needle and insulated therefrom, a spring terminal member connected to said spiral sleeve and a second spring terminal member connected to said needle, the connecting portions of said spring terminal member being bent at relatively right angles to the main body portions of the spring terminal, the main body portions of said spring terminals being adapted for making electrical contact with sai cord tips.

12. In combination, a needle having an insulating member and sleeve mounted thereon, a spiral sleeve mounted on said insulating sleeve, spring terminal members connected respectively to said needle and to said spiral sleeve, a cap mounted on said spiral sleeve and a housing fitted to said -cap and enclosing said spring terminal members.

13. In combination, a needle having an insulating sleeve mounted thereon, a spiral sleeve mounted on said insulating sleeve, a. cap fitted tightly on said spiral sleeve and a housing, one end of which is adapted to t over and be held by said cap.

14. In combination, a needle, a spiral sleeve member mounted thereon and insulated therefrom, spring terminal members con-l nected to the spiral sleeve and tothe needle, a housing for said terminal members, cord tips adapted to cooperate with said spring terminals for making contact therewith, said spring terminals holding said cord tips rmly against the inner wall of said'housing.

15. In combination, a housing, a pair of spring terminal members inclosed 1n said housing and having projections integral therewith extending longitudinally of the housing to the outside thereof, a pair of cord tips gripped between the inner wall of said housing and spring terminal members, said cordtips being released from said grip by drawing together said longitudinal projections.

16. A switch plug having a tip and a sleeve, insulatedfrom one another and adapted to engage the corresponding portions of a jack, said sleeve being cylindrical in shape and of a slightly enlarged diameter intermediate its ends.

17. A switch plug having a tip and a cylindrical spring sleeve of a slightly enlarged diameter intermediateI its ends, said sleeve and tip being insulated from one another and adapted to engage the corresponding portions of a jack.

In witness whereof, I hereunto subscribe my name this 15th day of April, 1925.

NEWTON C. SCHELLENGER. 

